Related papers: Lyman Break Galaxies and the Reionization of the I…
With SIRTF and NGST in the offing, it is interesting to examine what the stellar populations of z~3 galaxies models imply for the existence and nature of Lyman-break galaxies at higher redshift. To this end, we ``turn back the clock'' on…
There has been great progress in recent years in discovering star forming galaxies at high redshifts (z>5), close to the epoch of reionization of the intergalactic medium (IGM). The WFC3 and ACS cameras on the Hubble Space Telescope have…
Star-forming galaxies at redshifts z>6 are likely responsible for the reionization of the universe, and it is important to study the nature of these galaxies. We present three candidates for z~7 Lyman-break galaxies (LBGs) from a 155…
We determine the abundance of i'-band drop-outs in the HST/ACS GOODS surveys and the Hubble Ultra Deep Field (UDF). The majority of these sources are likely to be z~6 galaxies whose flux decrement arises from Lyman-alpha absorption. We have…
Intense, compact, star-forming galaxies are rare in the local Universe but ubiquitous at high redshift. We interpret the 0.1-22 um spectral energy distributions (SED) of a sample of 180 galaxies at 0.05<z<0.25 selected for extremely high…
We have discovered six galaxies with spectroscopically confirmed redshifts of 4.8<z<5.8 in a single 44 square arcminute field imaged deeply in R, I and z-bands. All the spectra show an emission-line in the region around 7000-8400 angstroms…
We report on the status of large surveys of photometrically selected star forming galaxies at z~3 and z~4, with particular emphasis on both the advantages and the limitations of selecting objects using the ``Lyman break'' technique. Current…
We present initial results of a survey for star-forming galaxies in the redshift range 3.8 < z < 4.5. This sample consists of a photometric catalog of 244 galaxies culled from a total solid angle of 0.23 square degrees to an apparent…
The fraction of ionizing photons that escape from young star-forming galaxies is one of the largest uncertainties in determining the role of galaxies in cosmic reionization. Yet traditional techniques for measuring this fraction are…
The goal of searching back in cosmic time to find star formation during the epoch of reionization will soon be within reach. We assess the detectability of high-redshift galaxies by combining cosmological hydrodynamic simulations of galaxy…
Lyman alpha galaxies at high redshifts offer a powerful probe of both the formation of galaxies and the reionization of the intergalactic medium. Lyman alpha line emission is an efficient tool for identifying young galaxies at high…
Four recent observational results have challenged our understanding of high--redshift galaxies, as they require the presence of far more ultraviolet photons than should be emitted by normal stellar populations. First, there is significant…
We study the physical characteristics of galaxies at 6.3 < z < 8.6, selected from deep near-infrared imaging with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope. Accounting for the photometric scatter using simulations,…
Detections and non-detections of Lyman alpha (Ly$\alpha$) emission from $z>6$ galaxies ($<1$ Gyr after the Big Bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization's mid-stages, but…
We present new measurements of the evolution in the Lyman break galaxy (LBG) population between z~4 and z~6. By utilizing the extensive multiwavelength datasets available in the GOODS fields, we identify 2443 B, 506 V, and 137 i'-band…
We use a semi-analytic model of galaxy formation in hierarchical clustering theories to interpret recent data on galaxy formation and evolution, focussing primarily on the recently discovered population of Lyman-break galaxies at $z\simeq…
The quest to discover the most distant galaxies has developed rapidly in the last decade. We are now exploring redshifts of 6 and beyond, when the Universe was less than a billion years old, an epoch when the previously-neutral…
If enough of their Lyman limit continuum escapes, star-forming galaxies could be significant contributors to the cosmic background of ionizing photons. To investigate this possibility, we obtained the first deep imaging in the far…
We present a semi-analytical model of star formation which explains simultaneously the observed UV luminosity function of high redshift Lyman break galaxies (LBGs) and luminosity functions of Lyman-alpha emitters. We consider both models…
We determine the space density of UV-luminous star-burst galaxies at z~6 using deep HST ACS SDSS-i' (F775W) and SDSS-z' (F850LP) and VLT ISAAC J and K_s band imaging of the Chandra Deep Field South. We find 8 galaxies and one star with…